Apparatus and method for removing impurities from aqueous hydrogen peroxide

Abstract

Impurities are removed from aqueous hydrogen peroxide by treating the aqueous hydrogen peroxide by reverse osmosis, cation-exchanging the aqueous hydrogen peroxide and anion-exchanging the aqueous hydrogen peroxide, and the treated ultra-pure hydrogen peroxide can be used in the electronics industries.

What is claimed is: 
     
       1. An apparatus for removing impurities from aqueous hydrogen peroxide, comprising: a source of aqueous hydrogen peroxide;   a means for introducing aqueous hydrogen peroxide from said source into a main line,   said main line comprising a means for reverse osmosis treatment, a means for cation-exchange treatment and a means for anion-exchange treatment, and   a means for discharging treated aqueous hydrogen peroxide from said main line; wherein said means for reverse osmosis treatment comprises a reverse osmosis treatment equipment, a reservoir tank and a liquid transporting equipment, said tank and liquid transporting equipment being provided on an upstream side of said reverse osmosis treatment equipment; and   which further comprises a recycling line from a feed side of said reverse osmosis treatment equipment to said reservoir tank, and a transition metal scavenging equipment in said recycling line.   
     
     
       2. The apparatus according to claim 1, wherein said means for reverse osmosis treatment comprises a reverse osmosis treatment equipment having a composite membrane of an aromatic crosslinked polyamide. 
     
     
       3. The apparatus according to claim 1, wherein said cation-exchange means for treatment comprises a styrene base gel type strongly acidic ion-exchange resin. 
     
     
       4. The apparatus according to claim 1, wherein said anion-exchange treatment comprises a styrene base gel type strongly basic ion-exchange resin. 
     
     
       5. The apparatus according to claim 1, wherein said transition metal scavenging equipment comprising at least one resin selected from the group consisting of cation-exchange resins, anion-exchange resins and chelate resins. 
     
     
       6. The apparatus according to claim 1, wherein said means for introducing aqueous hydrogen peroxide comprises a reservoir tank and means for transporting liquid from said reservoir to said main line. 
     
     
       7. The apparatus according to claim 1, wherein all parts of said main line that contact the liquid are made of a material resistant to hydrogen peroxide. 
     
     
       8. The apparatus according to claim 7, wherein all parts of said main line that contact the liquid are made of polytetrafluoroethylene. 
     
     
       9. An apparatus for removing impurities from aqueous hydrogen peroxide, comprising in an upstream to downstream order: a reservoir tank containing aqueous hydrogen peroxide;   a means for transporting aqueous hydrogen peroxide from said reservoir tank into a main line;   said main line comprising a first means for cation-exchange treatment of impure aqueous hydrogen peroxide, a means for reverse osmosis treatment of impure aqueous hydrogen peroxide, a means for anion-exchange treatment of impure aqueous hydrogen peroxide and a second means for cationic-exchange treatment of impure aqueous hydrogen peroxide;   a means for discharging treated aqueous hydrogen peroxide from said main line; and   said apparatus further comprising a recycling line from a feed side of said reverse osmosis treatment equipment to said reservoir tank, and a transition metal scavenging equipment in said recycling line;   wherein said means for reverse osmosis treatment comprises a reverse osmosis treatment equipment, a reservoir tank and a liquid transporting equipment, said tank and liquid transporting equipment being provided on an upstream side of said reverse osmosis treatment equipment.